If f and g are real functions defined by f (x) = x² + 7 and g (x) = 3x + 5, find each of the following
f (3) + g (– 5)

Question

If f and g are real functions defined by f (x) = x2 + 7 and g (x) = 3x + 5, find each of the followingf (3) + g (– 5)

Philoid · Accepted Answer

Given: f and g are real functions such that f (x) = x² + 7 and g (x) = 3x + 5

To find: f (3) + g (– 5)

Explanation: the given

f (x) = x² + 7

Now putting x = 3 in above function, we get

f (3) = 3² + 7 = 9 + 7 = 16……..(i)

and also given

g (x) = 3x + 5

Now putting x = -5 in above function, we get

g (-5) = 3(-5) + 5 = -15 + 5 = -10…………(ii)

Adding equation (i) and (ii), we get

f (3) + g (– 5) = 16-10 = 6